Database version Rename

[cblgh]

i renamed protocol version to database version and used an int to represent it instead as it doesn't make sense to have minor & patch on something like this.

lmk what else we can do here before we merge into master

this will be required for cabal-cli's multi cabal pr

[okdistribute]

What other modules break by changing the external api for protocolVersion to databaseVersion? This would probably be a major bump of cabal-core.

Using a separate version number than the core library that's published on npm might cause confusion later in time. With a small distributed set of contributors, reducing the number of variables at play can help with groking potential bugs or mismatches in versions. What if we used the version from package.json?

[cblgh]

@Karissa nothing will break as nobody is relying on protocolVersion yet, it's just the multi-cabal pr right now. which is why i felt okay with doing a breaking rename like this

(also there's a major bump in there too) i'm mixin' my semvers up because i'm too fast 🔥

see the discussion here #25

[hackergrrl]

Is the code that changes the ~/.cabal/archives dir name already in master, or can that get into this PR too?

[cblgh]

@noffle it's not in master, but in the multi-cabal pr here cabal-club/cabal-cli#89

(i'm not sure how i would bring it into the cabal-core pr)

[hackergrrl]

Ah, of course!

My thinking was "gosh it'd be nice if we could get in the db-dir changes so we can test that separately from the multi-cabal work".